A buzzing “perfect storm” of stress factors occurring simultaneously may have caused the large honeybee die-off that transpired from fall 2006 into spring 2007.

Three western honeybee experts agree that the apicultural debacle, labeled by some as colony collapse disorder (CCD), caused the deaths of millions of bees across the country and threatened bee numbers needed to pollinate the nation’s bounty of crops.

“We’re using CCD as a name, title, or description of what beekeepers see when they find a box emptied of most adult bees with maybe a handful of young bees and the queen remaining,” says University of California (UC) Cooperative Extension Apiculturist Eric Mussen.

In such a case, “If there was brood in there, it has been neglected, it’s dying, and it’s in bad shape,” Mussen says, “There’s generally plenty of stored honey and pollen from last fall, but something happened to the bees, and they couldn’t hang in there. Bees tend to fly off into the field to die.”

Western farmers and beekeepers are closely attuned to the buzz-less realities of the perplexing honeybee disappearance.

The good news: The massive bee die off didn’t reduce numbers enough to impact the gargantuan spring pollination demands of Western crops like almonds, tree fruit, melons, alfalfa seed, and others. At press time, adequate bee numbers to pollinate eastern U.S. crops like blueberries was uncertain.

The bee casualties and related worries helped spike colony rental rates to about $150 per hive for almonds this spring. California’s estimated 640,000-acre almond industry required from 1 to 1.5 million of the nation’s 2 million honeybee colonies for 2007 spring pollination. Almond acreage is expected to blanket about 800,000 California acres by about 2010, stretching even further demand for honeybees.

California beekeepers maintain about 500,000 colonies annually, Mussen says. The balance is trucked in from areas mostly west of the Mississippi River, ahead of the spring bloom.

Bee stress factors

The “perfect storm” is likely the result of an accumulation of bee stress factors. Mussen, and two researchers at the U.S. Department of Agriculture’s bee research center at Tucson, Ariz., agree that nutritional deficiency is likely a stress factor.

Honeybees were lacking a good mix of pollens, according to Mussen, who is based at UC-Davis.

“It may be a malnutrition stress situation. Pollen is where honeybees get important proteins, fats, minerals, and vitamins.”

Pollen falls into two classes. Some, like pollen from almonds and other deciduous trees, provides bees a nutritional boost in the spring. Although dandelions are a bee favorite, its yellow flowers deliver nutritionally-deficit pollen, Mussen says. Bees also like field corn and pine pollen, but the fiber-based pollen lacks essential nutrients.

The adage, “You are what you eat,” also applies to honeybees. Without a smorgasboard of nutrition-filled pollens, the brood (bee family) is somewhat unhealthy. If the next set of adult bees is also malnourished, then the next brood will be even more nutritionally challenged.

Moving bees by truck across the country is another stress. “It bangs the bees around,” Mussen says. He has heard some beekeepers report queen bee losses in the 10 percent range from transportation stress.

“Fortunately, honeybee colonies tend to figure out that the queen is damaged and can rear a new one. If it’s the right time of year and drones are around, the new queen can be mated and the colony can come back.”

Mussen also says pesticides can be a bee stress factor.

“Most commercial honeybees in California are exposed to pesticides, (so the impact) depends on how many times they are used in pollination,” he says. “You almost can’t get away scot-free from pesticide exposure when you’re working around agricultural crops.”

Mother Nature also deals repeated stresses to bees through rain, wind, and temperature extremes. Temperatures of 100-degrees plus in California during the summer of 2006 caused bees to lose interest in seeking food.

“If you opened up the brood nest and looked at the combs on the inside where the queens are normally working and the eggs are, you wouldn’t find anything. It was too hot. They had moved to the edges of the brood nest and there weren’t many eggs.”

Virus diseases may have played a role. Varroa mites reduce the bee’s immune system response to infections.

“This past season may have been the perfect storm for honeybees, everything just kind of ganged up on them and perhaps they couldn’t take it.”

Bee solutions

Honeybee researchers from respected institutions searched to find the bee death source, collecting dead throughout the U.S.

Collections have been frozen, some wrapped in aluminum foil to avoid contamination, and some placed some in alcohol for preservation. Also collected were bees from collapsed colonies, colonies in a stage of collapse, and healthy colonies.

Researchers hope these collections will reveal a common thread for the deaths. But Mussen expects it will be difficult to find.

He conducts some bee research at UC, but lacks the equipment that other institutions have. In the 1990s, retirements and budget challenges caused cutbacks at the university’s Harry Laidlaw Jr. Honeybee Research Facility.

Due to expanding needs by California agriculture for increased pollination services, the UC announced plans in May to jump-start the bee lab. The UC recently hired bee breeder and geneticist Susan Cobey from Ohio State University.

In addition, the UC will hire an entomology professor to specialize in bee pollination biology. A $500,000 bee lab renovation is on the drawing board, plus the creation of a $1 million endowment fund to support honeybee genetic and pollination biology research.

Today, the U.S. government’s key bee research facility in the West is the U.S. Department of Agriculture-Agricultural Research Service’s Carl Hayden Bee Research Center at Tucson, Ariz.

Lead researcher Gloria DeGrandi-Hoffman has spent 29 years in honeybee research, including 22 years at the Hayden bee facility.

“The laboratory’s mission is to provide strong colonies for the pollination of agricultural crops,” she says, “We look at bee nutrition as a large part of maintaining strong colonies.”

Are honeybees getting required nutrition through natural pollen?

“As much as U.S. agriculture needs honeybees, it’s very challenging to find areas where you can sufficiently feed bees on natural pollen, particularly during times of the year when you can have 8,000 to 10,000 colonies in a single area waiting to be moved into a crop like almonds.”

DeGrandi-Hoffman, like many bee researchers, is puzzled by the honeybee losses.

“When you have a collapsed colony, there aren’t a lot of bodies for autopsies. We examine food sources in the colony looking for contaminates, but there are hundreds of compounds…If you don’t know what they are, it’s like looking for a needle in a haystack.”

“If you find a pathogen, you don’t know if it’s a cause or the result of a cause. It’s a very difficult thing scientifically to pin down.”

DeGrandi-Hoffman and other researchers at the Arizona facility have worked tirelessly with Western farmers and beekeepers, who asked for the lab’s assistance in developing a nutritionally sound, enhanced bee supplement to foster healthier bees to meet Western agricultural demands.

After four years of research, a new bee supplement called MegaBee is ready for production, with plans for market availability by August 2007. Available as a liquid and in a patty form, the new supplement is likely to be manufactured at Yuma, Ariz.

“MegaBee was tested last fall and winter (2006-2007) on bee colonies getting ready to go into almonds. It was a good time to test because there wasn’t much out there for bees to forage on. Essentially they were living off the MegaBee diet. Results look very good,” DeGrandi-Hoffman says.

MegaBee, developed through a joint endeavor with a private company, will join a handful of existing bee supplement products on the market.

“To get our ARS science into the hands of U.S. agriculture, we set up a cooperative research and develop agreement with an ARS lab partner,” she says, “The research partnership ultimately delivers a product to market.

The agreement is a win-win opportunity, she said. ARS invests its expertise into creating an enhanced bee diet, while the private company helps create the supplement and conducts research on other ARS bee projects.

“We’ve worked with Gordon Wardell, who offers expertise in honeybee nutrition and microbiology. We have expertise in honeybee crop pollination and chemistry, so we partnered to create this diet.”

Wardell, the creative partner, purchased MegaBee licensing rights from the government, DeGrandi-Hoffman says. She and the Almond Board of California and Grandi-Hoffman contacted Wardell to create the bee supplement.

In his research, Wardell says, “I asked the bees” what they wanted to eat.

“I put dishes of food on a table. The bees came nosing into it – it was a smorgasbord. At the end of the day, we’d weigh the dishes to see what the bees liked and didn’t like. Then we looked at the nutritional makeup and started combining and mixing until we had a formula for which bees had a high preference.”

MegaBee, also called the Tucson Bee Diet, will first be distributed to major honeybee supply houses in 50-pound bags. Beekeepers then add their own sugar syrup to the mix. Pound for pound, the supplement is more digestible than natural pollen, Wardell says.

“In Bakersfield we found, for a pound of product going in, that we had more square inches of brood coming out— even more so than with natural pollen.

Wardell is the president of S.A.F.E. Research & Development, LLC (Sensible Alternatives for the Environment).

CCD answers this summer?

The answer to CCD could be found this summer, Grandi-Hoffman says.

“If bee populations rebound and begin to build this summer, there is an argument that nutritional stresses in fall 2006 may have been an underlying cause for the problem.

Dry conditions in many parts of the country last fall reduced good nectar flow, so fewer good fall pollens were taken into colonies.

“Bees rely on fall pollens to rear a brood and take them through the winter. It was a hard fall, followed by a warm winter, and bees were out flying. There weren’t any resources (food) out there, so the bees were burning up flight muscles.”

If colonies don’t grow this summer, then the bee die off suggests a pathogen-based problem, Grandi-Hoffman says.

Colonies average 10,000 to 20,000 bees in the winter, and 40,000 to 50,000 in the summer.

“If colonies build this summer and well-fed colonies grow, then it points to nutrition. This summer may tell where we are with this,” she says.